view tests/test-drawdag.t @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

  $ cat >> $HGRCPATH<<EOF
  > [extensions]
  > drawdag=$TESTDIR/drawdag.py
  > [experimental]
  > evolution=true
  > EOF

  $ reinit () {
  >   rm -rf .hg && hg init
  > }

  $ hg init

Test what said in drawdag.py docstring

  $ hg debugdrawdag <<'EOS'
  > c d
  > |/
  > b
  > |
  > a
  > EOS

  $ hg log -G -T '{rev} {desc} ({tags})'
  o  3 d (d tip)
  |
  | o  2 c (c)
  |/
  o  1 b (b)
  |
  o  0 a (a)
  
  $ hg debugdrawdag <<'EOS'
  >  foo    bar       bar  foo
  >   |     /          |    |
  >  ancestor(c,d)     a   baz
  > EOS

  $ hg log -G -T '{desc}'
  o    foo
  |\
  +---o  bar
  | | |
  | o |  baz
  |  /
  +---o  d
  | |
  +---o  c
  | |
  o |  b
  |/
  o  a
  
  $ reinit

  $ hg debugdrawdag <<'EOS'
  > o    foo
  > |\
  > +---o  bar
  > | | |
  > | o |  baz
  > |  /
  > +---o  d
  > | |
  > +---o  c
  > | |
  > o |  b
  > |/
  > o  a
  > EOS

  $ hg log -G -T '{desc}'
  o    foo
  |\
  | | o  d
  | |/
  | | o  c
  | |/
  | | o  bar
  | |/|
  | o |  b
  | |/
  o /  baz
   /
  o  a
  
  $ reinit

  $ hg debugdrawdag <<'EOS'
  > o    foo
  > |\
  > | | o  d
  > | |/
  > | | o  c
  > | |/
  > | | o  bar
  > | |/|
  > | o |  b
  > | |/
  > o /  baz
  >  /
  > o  a
  > EOS

  $ hg log -G -T '{desc}'
  o    foo
  |\
  | | o  d
  | |/
  | | o  c
  | |/
  | | o  bar
  | |/|
  | o |  b
  | |/
  o /  baz
   /
  o  a
  
  $ hg manifest -r a
  a
  $ hg manifest -r b
  a
  b
  $ hg manifest -r bar
  a
  b
  $ hg manifest -r foo
  a
  b
  baz

Edges existed in repo are no-ops

  $ reinit
  $ hg debugdrawdag <<'EOS'
  > B C C
  > | | |
  > A A B
  > EOS

  $ hg log -G -T '{desc}'
  o    C
  |\
  | o  B
  |/
  o  A
  

  $ hg debugdrawdag <<'EOS'
  > C D C
  > | | |
  > B B A
  > EOS

  $ hg log -G -T '{desc}'
  o  D
  |
  | o  C
  |/|
  o |  B
  |/
  o  A
  

Node with more than 2 parents are disallowed

  $ hg debugdrawdag <<'EOS'
  >   A
  >  /|\
  > D B C
  > EOS
  abort: A: too many parents: C D B
  [255]

Cycles are disallowed

  $ hg debugdrawdag <<'EOS'
  > A
  > |
  > A
  > EOS
  abort: the graph has cycles
  [255]

  $ hg debugdrawdag <<'EOS'
  > A
  > |
  > B
  > |
  > A
  > EOS
  abort: the graph has cycles
  [255]

Create obsmarkers via comments

  $ reinit

  $ hg debugdrawdag <<'EOS'
  >       G
  >       |
  > I D C F   # split: B -> E, F, G
  >  \ \| |   # replace: C -> D -> H
  >   H B E   # prune: F, I
  >    \|/
  >     A
  > EOS
  1 new orphan changesets

  $ hg log -r 'sort(all(), topo)' -G --hidden -T '{desc} {node}'
  *  G 711f53bbef0bebd12eb6f0511d5e2e998b984846
  |
  x  F 64a8289d249234b9886244d379f15e6b650b28e3
  |
  o  E 7fb047a69f220c21711122dfd94305a9efb60cba
  |
  | x  D be0ef73c17ade3fc89dc41701eb9fc3a91b58282
  | |
  | | x  C 26805aba1e600a82e93661149f2313866a221a7b
  | |/
  | x  B 112478962961147124edd43549aedd1a335e44bf
  |/
  | x  I 58e6b987bf7045fcd9c54f496396ca1d1fc81047
  | |
  | o  H 575c4b5ec114d64b681d33f8792853568bfb2b2c
  |/
  o  A 426bada5c67598ca65036d57d9e4b64b0c1ce7a0
  
  $ hg debugobsolete
  112478962961147124edd43549aedd1a335e44bf 7fb047a69f220c21711122dfd94305a9efb60cba 64a8289d249234b9886244d379f15e6b650b28e3 711f53bbef0bebd12eb6f0511d5e2e998b984846 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'split', 'user': 'test'}
  26805aba1e600a82e93661149f2313866a221a7b be0ef73c17ade3fc89dc41701eb9fc3a91b58282 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '9', 'operation': 'replace', 'user': 'test'}
  be0ef73c17ade3fc89dc41701eb9fc3a91b58282 575c4b5ec114d64b681d33f8792853568bfb2b2c 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '13', 'operation': 'replace', 'user': 'test'}
  64a8289d249234b9886244d379f15e6b650b28e3 0 {7fb047a69f220c21711122dfd94305a9efb60cba} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}
  58e6b987bf7045fcd9c54f496396ca1d1fc81047 0 {575c4b5ec114d64b681d33f8792853568bfb2b2c} (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'prune', 'user': 'test'}

Change file contents via comments

  $ reinit
  $ hg debugdrawdag <<'EOS'
  > C       # A/dir1/a = 1\n2
  > |\      # B/dir2/b = 34
  > A B     # C/dir1/c = 5
  >         # C/dir2/c = 6
  >         # C/A = a
  >         # C/B = b
  > EOS

  $ hg log -G -T '{desc} {files}'
  o    C A B dir1/c dir2/c
  |\
  | o  B B dir2/b
  |
  o  A A dir1/a
  
  $ for f in `hg files -r C`; do
  >   echo FILE "$f"
  >   hg cat -r C "$f"
  >   echo
  > done
  FILE A
  a
  FILE B
  b
  FILE dir1/a
  1
  2
  FILE dir1/c
  5
  FILE dir2/b
  34
  FILE dir2/c
  6